rawtransportchannel.h

本人收集整理的一份c/c++跨平台网络库

/*
 * libjingle
 * Copyright 2004--2005, Google Inc.
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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#ifndef _CRICKET_P2P_BASE_RAWTRANSPORTCHANNEL_H_
#define _CRICKET_P2P_BASE_RAWTRANSPORTCHANNEL_H_

#include "talk/base/messagequeue.h"
#include "talk/p2p/base/transportchannelimpl.h"
#include "talk/p2p/base/rawtransport.h"
#include "talk/p2p/base/candidate.h"

namespace cricket {

class Port;
class Connection;
class StunPort;
class RelayPort;
class PortAllocator;
class PortAllocatorSession;

// Implements a channel that just sends bare packets once we have received the
// address of the other side.  We pick a single address to send them based on
// a simple investigation of NAT type.
class RawTransportChannel : public TransportChannelImpl, 
    public talk_base::MessageHandler {
 public:
  RawTransportChannel(const std::string &name,
		      const std::string &session_type,
                      RawTransport* transport,
                      PortAllocator *allocator);
  virtual ~RawTransportChannel();

  // Implementation of normal channel packet sending.
  virtual int SendPacket(const char *data, size_t len);
  virtual int SetOption(talk_base::Socket::Option opt, int value);
  virtual int GetError();

  // Returns the raw transport that created this channel.
  virtual Transport* GetTransport() { return raw_transport_; }

  // Creates an allocator session to start figuring out which type of port we
  // should send to the other client.  This will send SignalChannelMessage once
  // we have decided.
  virtual void Connect();

  // Resets state back to unconnected.
  virtual void Reset();

  // We don't actually worry about signaling since we can't send new candidates.
  virtual void OnSignalingReady() {}

  // Handles a message setting the remote address.  We are writable once we
  // have this since we now know where to send.
  virtual void OnChannelMessage(const buzz::XmlElement* msg);

 private:
  RawTransport* raw_transport_;
  PortAllocator* allocator_;
  PortAllocatorSession* allocator_session_;
  StunPort* stun_port_;
  RelayPort* relay_port_;
  Port* port_;
  bool use_relay_;
  talk_base::SocketAddress remote_address_;

  // Called when the allocator creates another port.
  void OnPortReady(PortAllocatorSession* session, Port* port);

  // Called when one of the ports we are using has determined its address.
  void OnCandidatesReady(PortAllocatorSession *session,
                         const std::vector<Candidate>& candidates);

  // Called once we have chosen the port to use for communication with the
  // other client.  This will send its address and prepare the port for use.
  void SetPort(Port* port);

  // Called once we have a port and a remote address.  This will set mark the
  // channel as writable and signal the route to the client.
  void SetWritable();

  // Called when we receive a packet from the other client.
  void OnReadPacket(Port* port, const char* data, size_t size,
                    const talk_base::SocketAddress& addr);

  // Handles a message to destroy unused ports.
  virtual void OnMessage(talk_base::Message *msg);

  DISALLOW_EVIL_CONSTRUCTORS(RawTransportChannel);
};

}  // namespace cricket

#endif  // _CRICKET_P2P_BASE_RAWTRANSPORTCHANNEL_H_